Electron-discharge device



Sept. 14 1926. 1,600,060

H. J. NOLTE ELECTRON DISCHARGE DEVICE Filed Sept. 18, 1923 w w up 22 23,

Inventor l-le'm- J. Nolte,

His Attorney.

Patented Sept. 14, 1926.

UNITED STATES PATENT" OFFICE.

HENRY J. R'OL'IE, OI 'BCHENECTAIDY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

nnncrnou-msolmnen nnvrcn.

Application fled September 18, 1923. Serial No. 663,471.

My present invention, which is a continuation in part of my rior applicat1on, Ser1al No. 443,005, filed ebruary 7, 1921, relates to electron discharge devices, and more particularly to devices of the type employing at least three electrodes, comprising a cathode, an anode and a grid member for controlhng the passage .of an electron stream between cathode andanode.

The object of my invention is to provide a simple and efiicient construction for such devices which will be particularly adapted for controlling large amounts of: power. In carrying my invention into efl'ect'I provide an evacuated receptacle, which iscompos'ed in art of lass or vitreous material throu h which lea ing-in wires may. be read y sealed, and in art of metal, the metal part of the reoeptac e being adapted'to serve as anode for the device.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims, the invention itself, however, will best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. lzis a view artly in section of. one of my improved evices; Fig. 2 is a view of the grid and the structure whereby it is supported; Figs. 3 and 4 are detail views of portions of the grid structure, and Figs. 5, 6 and 7 are detail views of a supporting structure for the grid which may be substituted for the form shown'in Figs. 3 and 4, while Fig. 8 shows a detail of the grid end rings.

As indicated in the drawing, I provide an evacuated receptacle comprismg a Pertion 1 of glass and a portion 2 of metal.

The lass portion is sealed to the metal portion y means of a thin metal ring 3 w ch is preferably of copper or an alloy having substantially the, same coefiicient of expansion as the glass of which the part 1 is composed. This ring 3 is soldered or welded to the portion 2 and forms a gas-tight seal with the glass at the region'4 where it is surrounded by the glass wall of the portion 1. The cathode 5, which is preferably of tungsten, is supported. within the receptacle by means of supporting arms 6, 7 and 8, the arms 6 and? also serving as supply conductors to the cathode. that a large heating current must be supplied to the cathode in order to obtain a large electron emission and large output from the device, the leading-in conductors 9 and 10 are subdivided into a plurality of parallel wires of smaller diameter at the region 11 where they are sealed through the wall of the .reentrant tubular portion 12 of the glass member 1 in order that a gas tight seal may be made more readily than it can be made with a single large conductor.

The parallel portions of these leading-in expansion of the grid when .heated will occur in the direction of its diameter and the tendency of the grid to buckle and make contact with the filament or anode will be largely eliminated. The ends of these two sets of grid wires are securedto end rings 21 by means of binding wires wound around these rings. Supporting arms 20 are secured to these two rings and together with the rings form a rigid support for the grid. These supporting arms and the end rings preferably are made of tungsten or similar metal from which the occluded gas may easily be removed so there is no tendency for the evolution of gas when the parts are heated during the normal operation of the device. a

. I have indicated in Figs. 3, 4, and 8 of the drawing one convenient way of uniting the arms 20. with the rings 21. These rings are formed of a strip of metal 21 stamped out, as indicated in Fig. 4, with ears 22 projecting from its edges. The strip of metal 1s bent into the form of a ring, these ears bent over and the arms 20 inserted throughthe holes 23 in the ears 22. The arm 20, which passes through the holes 23 at the ends of. the strip which come opposite each other, also serves to hold the two ends of the-strip together. After the arms 20 are The grid 15.

In view of the fact I means of this construction the principal 78 inserted in these holes the ears may be squeezed or bent in such a way as to firmly grip the arms 20 and thereby secure the parts together without the necessity of any welded-or soldered joints. The grid structure described is supported in the desired position in the receptacle by means of a sleeve 24: which surrounds the reentrant tubular portion 12, and is securely fastened thereto by means of clamping screw 25. Supporting arms 26 are secured to this sleeve 24 and the members 20, which are of considerably smaller diameter than the diameter of the arms 26 are fastened to the arms 26 in the manner indicated at 27 in Fig. 2. For convenience in the construction of the device the end of the portion 2 of the receptacle may be left 0 en until the parts have been sealed toget er and then closed by means of a cap 28 which is soldered to the receptacle or welded thereto to form an air-tight joint.

In the modification shown in Figs. 5, 6 and 7, the rings for supporting the grid are made from flatmetal strips 29, which are provided with punched out portions 30, which are so formed that the arms 20 are embraced between these punched out portions and the main body of the strip, as indicated in Fig. 6. In this case also the arm 20, which passes through the openings formed by the punched out portions 30 at the ends of the strip serves to hold the two ends of the strip together. The strip 29, which forms the lower grid supporting ring is also provided with openings 31 and the upper ends of arms 26 are slotted to receive the grid supporting ring. The sides of the slots in the arms 26 are then pressed into the openings 31 as indicated in Fig. 7 thus securing the ring to the supporting arms without the necessity of any welded or soldered joint.

In the operation of the device described for the control of large energies, the anode 2 should be artificially cooled. This may be accomplished by placing it in a bath of water or other suitable cooling liquid and providing means to insure good circulation of the cooling liquid. In view of the fact, therefore, that the anode 2 will normally operate at a low temperature, it is possible to make use of metal for its construction having a comparatively low melting point. I have found that copper is very suitable for this purpose.

In the exhaustion of the device described, to remove all air as well as all the gases occluded in the metal parts, I prefer as a preliminary step to heat the anode 2 by means of heat radiated from the cathode 5. It is possible to heat the anode to red heat in this way and thereby drive off a large portion of the occluded gases. After the exhaustion has been carried on in this way until the evolution of gas is greatly decreased or substantially stopped, a source of potential is connected between cathode and anode so that the anode will be bombarded by electrons emitted from the cathode. At this point in the exhaust the cooling medlum is applied to the anode and the gas removed during this stage is therefore removed principally as a result of bombardment. Occluded gas is also removed from the gI' ]d. structure by bombarding the grid and its supporting parts by electrons given off from the cathode.

W'hile I have indicated and described the preferred embodiments of my invention, it will be understood that my invention 18 by no means limited to the particular structures shown as many modifications in the arrangement of parts and their relation to one another may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is 1. A support for an electrode comprising a strip of metal bent into the form of a ring, and a plurality of supporting arms which are surrounded by portions of' said metal strip and thereby secured to said ring, one of said arms being surrounded by portions located at opposite ends of the strip and serving to hold together the two ends of the strip.

2. A support for an electrode comprising a. strip of metal which is provided with stamped out portions and bent to form a ring, a plurality of supporting arms secured to said strip b said stamped out portions the ends of sai strip being held together by one of said supporting arms.

3. A support for an electrode comprising a strip of metal having portions which project away from the plane of the strip at opposite edges thereof and a plurality of supporting arms which are embraced by said projecting portions and thereby secured to said strip, said strip being bent into the form of a ring.

4. A support for an electrode comprising a strip of metal having portions which project away from the plane of the strip and a plurality of supporting arms which are embraced by said projecting portions and thereby secured to said strip, said strip being bent into the form of a ring and being held together by the coaction of one of said supporting arms and said projecting portions.

5. A support for an electrode comprising a strip of metal having portions which project away from the plane of the strip and a plurality of sup orting arms which are embraced by saici projecting portions and thereby secured to said strip, said stri being bent into the form of a ring, one 0 said arms being embraced by ojectin stri and serving to hold together the two end:

of the strip.

6. An electrode support comprising a cylindrioalgrid having a ring at one en thereof, supporting arms f0r said grid having slots in their ends for receiving said ring and openin s in said ring into which the sides of sai "slots are pressed thereby securin the ring to the su porting arms. n witnes whereo ,--I have heretmto set my hand this 17th da of September, 1923.

' HiDNRY J. NOL'LE. 

